Core UI is the same in DQ8 but it's a little more busy because of various additions like more skills, crafting etc. However, it's still pretty simple. Most options are no more than 2 presses deep and usually arranged in the place that makes a lot of sense. Yeah, there's no ability to reorganize skills as you see fit it's automatically grouped by type. Inventory limitations is on purpose so that you don't get access to everything in battle.
Some of those complaints extend to Persona 5 though. You can't reorder skills after you learn them, you can't sort items in the way you want it making it extremely annoying to go through a big list of them looking for the one you want, there are inconsistencies with how some equipment is shown in shop menus, several menus are located in confusing places until you get used to it, etc. There are a ton of problems when you start looking at it.
Then there's the audio-visual component. It's stylish as hell but a bunch of the menus aren't friendly to everyone, particularly the weapon & medicine shop menus which have a ton of colors and movement going on screen when you transition between menus. There's that obnoxious sound when going back in menus too...
Don't get me wrong, I like P5's menus but it's not a paragon of design and what not. There are lots of problems with it just like any other UI.
It's not so much the limitation itself that irks me but navigating and putting stuff in and out of your bag. It's just not acceptable especially when your game is on a device with touch screen.
As for Persona 5 I did not have a ton of problems with items but yes it would have been better if you could reorder there also. But the reason for that at least for me, you just use items way less frequently in Persona so it's less of an issue.
Design wise in my eyes it's way more forgivable when systems you use less often handle worse. In dq8 it just gets really annoying cause you're going to use items like the tamborine for the energy buff very frequently.
If we're talking about something really annoying in P5 I think what really deserves it is the equipment navigation. Once you go into a type of equipment section you can only switch between characters in that until you exit out and change to a different type. It makes party wide equipment changes unnecessarily more tiresome when L2/R2 could have been bound to changing equip category since those aren't doing anything. Navigating the military shop shows very similar problems. The only complaint I have with the medical shop is the way accessories are blocked off navigation wise you have to access them through the conversation list.
As for the audio visual component. Not sure what you mean there. Related to people maybe coming down on it being too busy? If that's what it is I mean I guess so. But to be honest that feels more like a complaint that subscribes very hard on this "thought of ideal UI design" where everything minimalistic = equals clarity among all these other rules that people swear by that I'm not sure I'm that fond of.
In general yes the core idea behind most of them is sound but the way it's usually applied not even only in games but also outside of it just lacks any kind of charm.
All I know is I'm very particular about that kind of stuff and I don't really have problems on that front with P5. Like you said it's stylish which does add a lot for me to the enjoyment of being in those menus, something that just isn't usually the case.
But at the same time I'm not going to say this is the holy grail any everyone should emulate and make everything full of animations and transitions.
Just that it fit P5 very well and thus made the menu part of the game fun to me which usually isn't something that one would enjoy.
I'm going to close out again repeating the importance of how the frequency of use vs the navigation ease is a huge factor in whether something really makes a negative impression. I mean it's not like I haven't noticed really awkward things navigation wise in P5 but what it comes down to is that the core systems work insanely well and all those side systems aren't that bad and used so often that I came down to hating them.
In DQ8 though just listing a few things that drove me goddamn nuts saving the game, not being able to make the maximum amount of something you have the ingredients for -> alchemy handles so unbelievably bad, way too much navigation required going through the buff rotations, transferring items from the main bag to characters, riding your tiger.
I'm almost sure there are other things I just forgot, but I think it's pretty clear that I have very active frustrations with DQ8 on that level.
I absolutely adore the goddamn game though after all I made it through the whole game + postgame something that I can't say about all the times I tried to get into Pokemon again which I last tried with X going to try again with Sun/Moon x_X. It basically comes down to that I feel like navigating in DQ and Pokemon can often feel like an insane timewaste while I don't think I felt that about P5.
I totally fell asleep halfway through posting so I hope it ended up somewhat coherent cause I had to reconnect to the thoughts I had from half the post I had left.
I'm just surprised how much people can get into what I consider small stuff like UI usability when I don't even think about it. It's not like it's an operating system where you actually need to have it as streamlined as possible so you're not constantly lost. Some of the menus in Persona 5 that people criticize are so simple to get around relative to real world systems that I'm just surprised anyone has anything to say about them at all.
It comes down to an attitude of seeking improvement always, so I'm not sure on why we should excuse really dumb UI just because it's game UI.
I mean I also found it very easy to get around but that doesn't mean I don't recognize unnecessary clunkiness.
